PROPERTIES AND REGULATION OF THE OXIDATIVE-PHOSPHORYLATION SYSTEM IN THE MYXOMYCETE PHYSARUM-POLYCEPHALUM .2. CHANGES IN CYTOCHROME CONTENT DURING THE CELL-CYCLE OF PHYSARUM-POLYCEPHALUM

Changes in the contents and ratios of cytochromes a, b, and c during the cell cycle of Physarum polycephalum were determined' The specific content of each of the three cytochrome groups was found to alter non-monotonously during the cell cycle. Distinct maxima in the contents of cytochromes a, b, and c in the middle of S phase and moderate maxima in the contents of cytochromes b and c in the middle of G2 phase were observed The growth rate of the Ph. polycephalum macroplasmodium, as indicated by the increase in its area, was shown to change periodically during the cell cycle. Maximal growth rate was observed at the end of S phase and in the second half of G2 phase. Thus, a correlation exists between the specific cytochrome content and growth rate of Physarum polycephalum cells.